Like so many people in theatre, Lucy Bailey can trace her entire career back to one man: Peter Hall. It's unlikely, though, that the veteran director himself would remember why. Bailey was 17 when she first laid eyes on him, and working as a switchboard operator at Glyndebourne opera house. Not that she could bring herself to sit by the telephone. "I spent most of my time under the stage," she admits, "looking at plays through the holes in the floorboards. It was a bit like Cinema Paradiso. It was like a drug. One day I asked someone, 'Who's that guy bumbling around on stage, whispering in people's ears?' And she said, 'That's Peter Hall, he's the director.' I thought, 'That's all right, then, I'll do that.'"

Now in her 40s (she's loath to give a precise age - "it's not worth it in this world"), Bailey has been directing ever since: first experimental theatre, then opera, then back to theatre in the mid-1990s when opera started feeling "ghettoised". Not that she abandoned music theatre altogether: with the Gogmagogs, the company she co-founded in 1995 with violinist Nell Catchpole, Bailey dramatised and revolutionised concert performances. But it was her more conventional pieces - not least her charged production of Tennessee Williams' Baby Doll, first seen in Birmingham in 1999, then at the National and in the West End - that made Bailey's name. She's now so highly rated that Dominic Dromgoole picked her out to direct the second play in his flagship opening season as artistic director of Shakespeare's Globe.

But while her CV suggests a brilliant career, Bailey says the reality isn't quite that simple. "I always thought that around the corner there would be this thing called success, and from then on you're simply successful. But that's only the way for a very few people. I'd like to get to the place where you can sit back a bit and choose what you want to do. I've been doing these fantastic projects every year, but it's still a struggle."

Bailey radiates sparky optimism, and yet readily admits to feeling defeated by the frustrations of freelance work. Asked how she deals with the inevitable lulls, she replies: "I don't. I just run and try and jump off bridges. I have no rationale; I'm never one to say, it's going to change next week. And you always feel as good as your last show - which is terrifying."

The accompanying sense of responsibility - to make each production perfect - is haunting Bailey at the moment. She's at the Globe to direct Titus Andronicus, one of the trickiest and bloodiest of Shakespeare's plays. It's bad enough that one character has her hands and tongue lopped off, while another is fed pies baked with the flesh of his own sons; Bailey also has to contend with the fact that only two productions of the play - those by Deborah Warner and Peter Brook - have been considered successful. No wonder Bailey says: "I was horrified when Dominic asked me to do Titus. I thought he was going to offer me Macbeth. I didn't know if I could live with the violence day by day."

The world of the play is considerably different from anything Bailey has directed before. Even when her work has shuddered with erotic violence - as in Baby Doll, or The Postman Always Rings Twice, which she took to the West End last year - the plays have revolved around women. Titus, by contrast, is set in "a male society, with male dictates and the male code of honour at the centre. It's a real challenge for me, directing a play with 20 men on stage."

Still, it hasn't proved that difficult: the cast, says Bailey, are "gorgeous". She has had problems with one member of the company, though: her designer - and partner - Bill Dudley. It's only the second time in their 20-year relationship that the couple have worked together; the first was in the early period of what was, for 10 years, an on-off affair. At the time they were off; there's something sweetly ingenuous about the way Bailey says: "We were on again after that, it worked extremely well."

This time, though, the pair have been "infuriated with each other. I've found a lot of the ways we work completely clashing." It hasn't helped that the couple also have two children to tend to, aged 10 and three. "It's domestic stress," says Bailey, "that's all it is. It's brought out a lot of tension, but we're still together, it hasn't totally ruined the marriage prospects. But we're never going to work together again - at least, not for another 20 years."

Still, Bailey isn't about to abandon her ambitions for the sake of a less demanding life. At the moment she's contemplating running her own theatre. "I've got so many projects I want to do, I don't want to wander around hoping that someone is going to employ me," she says. "I can't bear that any more. But the children are a confusion, because if I did run a theatre it could damage both of them. You have to treat the theatre as the place where you live, breathe, eat. It's your family, therefore it's in competition with your own family - unless you can drag them into it."

If her determination remains undimmed, it's because theatre is still the drug she first tasted aged 17, peeping through the floorboards at Glyndebourne. "It's absorbed my whole life," she says. "I don't have anything else. I have my children, but I clearly know that I need more than my children. My lifeline somehow is my work. It's the thing that keeps me as I am - the thing that keeps me sane".